Background
Biological diversity is not evenly distributed. There are many more species in the tropics than in high latitudes and there are likely many more species of birds today than 60 million years ago. In addition to the spatial and temporal variation in species richness, different groups of organisms also have varying levels of diversity. For instance, lobe-finned fishes, the group to which living coelacanths belong, have been extant since at least the Devonian (c. 400 million years ago) are much less species rich both today and in the past, compared with birds, a much younger group. Observed species richness is in large part a result of the processes of speciation (the evolution of new species) and extinction (the complete disappearance of a species). Likewise, the variation in species richness in different places, times and groups, is a consequence of differential speciation and extinction rates. While there are many studies that estimate these rates, complex factors have so far prevented us from a general overview of the rates of speciation and extinction across space, time and groups.
Masters project
This project seeks to better understand the variation in speciation and extinction rates across plant and animal groups, over the entire Phanerozoic (c. 500 million years of evolution). We will compile estimates of speciation and extinction from the published literature and seek to understand the variability among different organismal groups. The questions that will be answered are the following. Is some of the variation due to different methods applied to infer evolutionary rates? Do some groups of organisms have high rates of speciation and extinction and/or higher variation in these rates? Do dispersal mechanisms (e.g. planktotrophic versus non planktotrophic larvae), life history traits (e.g. those producing many progeny versus few) or body size have any explanatory power for these rates as often suggested in the literature, when looking across diverse groups of organisms?
To be able to systematically collate published data, the student will learn about state of the art as well as “traditional” approaches to estimate speciation and extinction rates. The student will verify published estimates by learning to implement diversification rates estimators in the popular programing language R and learn to perform statistical analyses, including meta-anlyses techniques, to test the hypotheses listed above. The student will be based at the EPA group at the NHM, UiO and have Lee Hsiang Liow as a main supervisor. The student will have opportunities to visit and spend time working in the labs of international project collaborators. EPA is a supportive, friendly and stimulating work environment where members work on related, but different projects, and have fun (both science and social!) together.